Fiberglass Wicks for Sampling of Water and Solutes in the Vadose Zone

Abstract

Sampling solute concentrations in the vadose zone provides an early‐warning system for groundwater pollution. Various sampling devices are available. This study evaluates the functionality of fiberglass wicks in a soil solution sampler. Fiberglass wicks act as a hanging water column, drawing water from the undisturbed field soil without external application of suction. Flow characteristics of wicks were observed in the laboratory by miscible‐displacement tests using Br and an organic dye. The matric potential in the wick as a function of flow rate was measured. Fiberglass wicks behaved like a porous medium that effectively could apply a suction to the soil while only minimally retarding the organic dye. The relationship between matric potential, moisture content, and unsaturated conductivity was determined for several wicks. Based on these relationships, a set of curves was produced depicting travel time of nonadsorbed chemicals and the matric potential in the wick as a function of flow rate. These curves can be used for selecting optimum wick length and diameter for a given sampler configuration.

Large zero-tension plate lysimeters for soil water and solute collection in undisturbed soils

“…Peters and W. Durner: Large plate lysimeters for soil water collection or passively by wick lysimeters (Boll et al, 1992;Jabro et al, 2008;Gee et al, 2009). The typically applied water sampling technique is the suction-cup lysimeter, which has been used since more than one century (Briggs and McCall, 1904).…”

Colloid-Facilitated Transport of Radionuclides Through The Vadose Zone

“…The second two flow rates are reasonable percolation rates in a sandy soil (Boll et al, 1992), and in this system correspond to matric potentials of 210 to 230 cm H 2 O, respectively, at the top of the fiberglass wick.…”

“…They were infiberglass wicks for their suitability to sample vadose zone troduced as pore water samplers by Brown et al (1986) colloids. We conducted transport experiments with five and have been used since in numerous studies (Gee and types of colloids: kaolinite, montmorillonite, ferrihydrite, Campbell, 1990;Boll et al, 1992 provided a detailed descripTreated and untreated (as shipped from supplier) wicks were characterized by scanning electron microscopy (SEM) and spetion of the Hanford formation sediments. The mineralogy of the sediments is dominated by quartz, phyllosilicates (primarily cific surface area determination.…”

“…An access trench is excavated along the study site with horizontal tunnels to install the PCAPS. The use of PCAPS in vadose zone sampling has been studied in detail with respect to solute and flux sampling (Holder et al, 1991;Poletika et al, 1992;Boll et al, 1992;BrandiDohrn et al, 1996;Goyne et al, 2000;Louie et al, 2000;Gee et al, 2002Gee et al, , 2003 and also with respect to mobileimmobile pore water (Landon et al, 1999). We assumed a priori that passive capillary samplers (PCAPS), as opposed to suction and zero-tension samplers, have the best chance of yielding a representative sample for reasons described below.…”

Automated System for Collecting Multiple, Sequential Samples from Soil Water Percolation Samplers under Continuous Vacuum

“…Continuous tension may be applied to percolation samplers at a constant potential via hanging water columns (Holder et al 1991;Boll, Steenhuis, and Selker 1992;Zhu, Fox, and Toth 2002) or by pneumatic vacuum (Cole, Gessel, and Held 1961;Cochran, Marion, and Leaf 1970;Kincaid et al 1979;Haines, Waide, and Todd 1982;Hergert 1986;Montgomery, Prunty, and Bauder 1987;Klocke et al 1993). Continuous tension applied to samplers may also be varied to match ambient soil conditions at the sampler-soil interface, either manually (Brye et al 1999) or automatically (Duke and Haise 1973;van Grinsven et al 1988;Lentz, Sojka, and Kincaid 1998;Lentz and Kincaid 2003;Masarik et al 2004).…”